Gas streams, such as engine crankcase blow-by gases (i.e., crankcase ventilation gases from the crankcases of diesel engines) carry substantial amounts of entrained oils (liquid) therein, as aerosol. In some instances, many of the oil (liquid) droplets within the aerosol are within the size 0.1-5.0 microns (μ). In addition, such gas streams also carry substantial amounts of fine particulate contaminants, such as carbon contaminants. Such contaminants often have an average particle size with the range of about 0.5-3.0 microns (μ).
In some instances, it is desired to vent such gases back into an airflow inlet, for the engine system of concern. Such systems will generally be referred to herein as “closed,” since the crankcase ventilation gases or engine blow-by gases are not vented to the atmosphere, but rather are retained within the system by being directed into the engine air intake for the system of concern. Typically, before such gases are directed to the engine intake, they are cleaned of a substantial portion of the aerosol and organic particulate contaminants therein.
An example such assembly is described in PCT/US 2008/071783 filed Jul. 31, 2008, and published on Feb. 5, 2009 as WO 2009/018454. Other assemblies are described in WO 2008/115985, published Sep. 25, 2008; and, WO 2008/157251, published Dec. 24, 2008.
Typically, such assemblies comprise a crankcase ventilation filter assembly having: a gas flow inlet; a gas flow outlet; and, a liquid drain outlet. Within the assembly a crankcase ventilation filter (or filter cartridge) is provided, through which the gases are directed in flowing from the gas flow inlet to the gas flow outlet. Within the filter or filter cartridge, liquid is coalesced and drained; the liquid being directed outwardly from the assembly through the liquid drain outlet. The filter or filter cartridge also removes a portion of the solid particulates within the gases. The filtered gases can then be vented or be directed through the gas flow outlet and to an airflow inlet for the equipment involved, for example into, or upstream from, an air cleaner.
In closed crankcase ventilation filter assemblies, sometimes a pressure regulator valve assembly is included within the crankcase ventilation filter assembly, or otherwise in association therewith. The function and operation of the pressure regulator valve assembly (i.e. pressure control valve) is to regulate the crankcase pressure to within acceptable limits in spite of varying pressure conditions at the crankcase ventilation filter assembly gas flow outlet. In particular, the regulator valve assembly prevents excessive negative pressure in the crankcase being caused by an underpressure condition at the gas flow outlet of the crankcase ventilation filter assembly being communicated back to the crankcase, i.e., through the crankcase ventilation filter assembly. A typical pressure control valve or pressure regulator valve assembly comprises a valve diaphragm biased against a spring, which closes or partially closes a gas stream through an outlet port of the crankcase ventilation filter system. For examples of such pressure regulation valve, see, for example, WO 2009/018454 and WO 2008/115985.
It is desired to improve pressure regulation with respect to crankcase ventilation filter systems.
This disclosure relates to an improved pressure regulation valve assembly usable, for example, with a crankcase ventilation filter assembly.